Hitherto, for the treatment of, for example, stomatitis, an ointment, a liquid medicine, or a tablet (for adherence) has been used. However, an ointment or a liquid medicament is dissolved in saliva or body temperature in a short period of time after application and swallowed, whereby a long lasting medical effect cannot be expected for these medicaments. Moreover since there is a fluctuation on each application amount in the case of applying the above-described medicament, a dosage of a constant amount is difficult.
On the other hand, a tablet can maintain the medical effect for a long period of time and improve the problem on the fluctuation of the dosage of the medicament but it is difficult to accurately apply the medicament to the affected portion in the oral cavity since the diameter thereof is as small as a few millimeters. Also, since such a tablet has a thickness of a little over 1 mm, it gives an incongruent feeling when applied to a portion in the oral cavity and hence it is not easy to apply a tablet, which sometimes results in detachment of the medicament from the applied portion. Accordingly, a sure medical effect cannot sometimes be expected in the case of the tablet.
As the result of various investigations on the optimum form of an adhesive medicament for this kind of purpose, the inventors have reached conclusions that the medicament must be in a form capable of covering a relatively broad area since an affected part is in an inconvenient position for observing from outside and that the medicament must be in a form of giving an incongruent feeling as less as possible.
It is necessary that the medicament meeting these conditions is a film-form medicament, is eatable, and is soluble in water but these requirements only are insufficient and further the form of medicament must be as thin as possible and must contain a sufficient amount of the medicament.